A circuit includes an amplifier having a first power terminal configured to be coupled to a supply voltage and a second power terminal configured to be coupled to a reference potential. The circuit further includes a first impedance element coupled between a first input terminal of the amplifier and a first output terminal of the amplifier. The circuit additionally includes a second impedance element coupled between the first input terminal and the reference potential. The amplifier is configured to output a first voltage at a second output terminal of the amplifier in response to the supply voltage being greater than an output voltage at the first output terminal of the amplifier. The amplifier is further configured to output a second voltage at the second output terminal of the amplifier in response to the supply voltage being less than the output voltage at the first output terminal of the amplifier.